Selecting the seven small catchments in Jiaodong Peninsula as the study area

the gully system was extracted using the SA model

and the fractal dimensions of the gully system were calculated by boxcounting method. The gully fractal characteristics and the coupling between the fractal dimensions of gully lengths and terrain parameters

and the land use types were analyzed to determine the characteristics of the gully evolution. The results showed that: (1) The fractal dimension of gully length in Mountain Watershed was larger than that in farming area

indicating the fractal feature of gully length was mainly controlled by the geological structure of the basin. (2) The gully-head density

ravine density

surface roughness

profile curvature

and terrain average gradient were found to have significant positive correlation with fractal dimension of gully length in the study catchments

while correlation between the area of catchment and the length of gully was insignificant. (3) There was significant positive correlation between the fractal dimension of gully length and the gully-head density

ravine density

with the correlation coefficients of 0.982 4 and 0.975 3

respectively

indicating that gully-head density and ravine density were the important parameters of the fractal characteristic of the valleys

as a simple indicator for estimating regional gully fractal characteristics and the fractal dimension. (4) There was significant positive correlation between the fractal dimension of gully length and the forest-grassland ratio and hilly area ratio

with the correlation coefficients of 0.893 and -0.919 8

respectively

indicating that the characteristics of the gully evolution was closely related to the large topographic contour under the control of geological structure

while little relation to the micro topography formed by the process of human activity.